Size M8 internal thread head diameter: 32mm, thread diameter: 8mm, screw length: 40mm. . Material The canvas screw set is made of PP material and electroplated iron. The surface of the nut is galvanized, which is not only wear-resistant, corrosion-resistant and high-temperature resistant, but also does not rust and has a long service life.. Star-shaped designScrews with star-shaped nut, easy to fix by hand, without using other tools. . Easy to replace Loose, broken or missing nut holder can be replaced with web handle lock nut. . Wide ApplicationThe M8 x 40mm thread clamp knobs are suitable for most machine tools, e.g. household, food and industrial instruments and appliances. .